Method and means for controlling electric energy.



H. W. LEONARD, DECD.

c. a. LEONARD. ADMINISTRATRIX.

METHOD AND MEANS FOR CONTROLLING ELECTRIC ENERGY.

APPLICATION FILED IULY 22.19l4- 1,298,974. Patented Apr. 1,1919.

3 SHEETS-SHEET I.

} ZERO TE/VPEIT YTURE COEFFICIENT H. W. LEONARD, DEC'D. c. s. LEONARD.ADMINISTRATRIX.

METHOD AND MEANS FOR CONTROLLING ELECTRIC ENERGY.

APPLICATION FILED JULY 22,19l4.

1,298,974, I Pafented Apr.,1,19 19,

3 SHEETSSHEET 2.

' ZERO TfMPEfi/ITURE c'osrrlcl EIVT ZERO TEMPE/ifiTl/HE wEfT/CIEAL H. W.LEONARD, DECD.

c. s. LEONARD. ADMINISTRATRIX.

METHOD AND MEANS FOR CONTROLLING ELECTRIC ENERGY.

APPLICATION FILED JULY 22. m4.

1,298,974, Patented Apr. 1, 1919.

' a s EET 3. F0 '5' H S SHEET 3 L g 1 E: 2 0000 3 1 2 3433 ZL'HO TEMPERI UHE C01 IFF/CIENT UNITED STATES PATENT OFFICE.

HARRY WARD LEONARD, 0F BRONXVILLE, NEW YORK;

CAROLYN G. LEONARD,

ADMINISTRATRIX OF SAID HARRY WARD LEONARD, DECEASED, ASSIGNOR TO B. WARDLEONARD INCORPORATED, A CORPORATION OF NEW YORK.

' Specification of Letters l atent.

Patented Apr. 1, 1919.

Application filed July 22 1914. Serial No. 852,840.

To all whom, it may concern: Be it known that I, HARRY WARD LEON- ARD, acitizen of the United States of America, residing at Bronxville, in thecounty of \Vestchester and- State of New York, have invented certain newand useful Improvements in Methods and Means for Controlling ElectricEnergy, of which the following is a full, clear, and exactspecification.

My invention relates to an improved method and means for controllingelectric energy, and is particularly applicable to the control ofelectric systems employed on motor cars for lighting, ignition, startingand other purposes; although my invention 1s also capable of variousother applications.

The usual electric system in use on motor cars consists of a dynamo,storage battery, incandescent lights, a starting motor for starting theengine by energy from the battery, and various other devices such asignition means, electric horns, etc.

In such a system itis important to properly control the currentdelivered by the dynamo or generator so as to keep the battery chargedand in good condition at all times. This resultis dependent very largelyupon proper control of the charging current and upon the electromotiveforce and current delivered by the generator. By means of my presentinvention I control this current so as to always maintain it withinproper limits and I cause a change of the limits to take place dependingupon changes in the circuit conditions and in the battery. My inventionpreserves the advantages of the control by a vibratory contactcontrolling the dynamo field and of having the vibratory contactresponsive to fluctuations in the current, which are much greater thanthe fluctuations in the voltage. I avoid unnecessarywaste of energy andthe objectionable driving ofi of the water of the electrolyte in thebattery after the battery is fully charged. I accomplish these and otherdesirable results while using a minimum number of automaticallycontrolled circuit contacts.

One of the rincipal features of my inven 'tion is the securing of abi-rate control. In

the present instance, when the voltage of the battery has reached acertain maximum, the

electro-responsive winding responsive to said voltage, causes a movementof a magnetic element, which movement causes a sudden and pronouncedchange in the reluctanbe of the magnet which controls a vibratory switchand which latter controls the generator field, resulting in a suddenreduction of the current supplied thereby. By this method of control,the battery may be charged at a certain proper average rate and thenafter its full. voltage is obtained, the average charging rate issuddenly reduced to a very much smaller amount, which serves to protectthe battery and maintain it in proper condition and avoids unnecessarywaste of energy, and also the objectionable rapid decomposition of thewater of the electrolyte in the battery.

In controlling means where the field of I the dynamo is automaticallycontrolled for controlling the current to the battery, it is verydesirable that the vibratory switch should move rapidly and positivelyto its two extreme positions under the influence of a sufficient forceto give reliability of 'operation and minimum wear. It is also desirablethat when the circuit contact of the vibratory switch be closed, that itbe rapidly and firmly closed with such force as to make good contact,preferably self-cleaning,- so as to avoid the ditficulties anddepreciation which would result from a loose, insufficient, slow oroxidized contact. Similarly when the switch is opened, it should beopened suddenly and by a force which will certainly and quickly open thecontacts even if they tend to stick together. These desirable conditionsare fulfilled by my invention. I

These and other objects and features of my invention will be understoodfrom the following description and accompanying drawings illustratingone embodiment of my invention.

Figure 1 is a plan view showing the construction of the controllingmeans, certain windings being also indicated in diagram; Fig. 2 is adiagram showing the electrical circuits and connections of the system asa whole; and Figs. 3 to 6 are similar diagrams showing modifications.

A gasolene engine. which serves as the driving engine of the motor caris indicated at 1 and is shown driving a direct current dynamo armature2. The speed of the dynamo will be directly proportionate to that corev6 is provided with two windings, a

shunt winding 7, and a series winding 8..

At one end of thismagnet is an armature 9 carryinga contact 10 which isadapted to make and break a circuit by engaging the stationar contact11. .The armature 9 as well as e two other armatures of the controllingmeans are mounted upon flexible spring supports 12 in the form of flatieces of th1n phosphor bronze, which are riveted to the armatures asshown or may be fixed thereto in any suitable manner. The opposite endsof these hosphor bronze strlps are clamped in a statlonary support inany desirable manner. This construction is rugged and durable and avoidsthe necessity of adjustment of any bearing and also avoids the y'ariablefriction of the usual pivot.

, A spring 13 is attached at one -end to the contact end of the armature9 and attached at its other end to a fixed part or hook and tends tohold the contact 10 away from contact 11.

The opposite end of the magnet 5 is provided with another armature 14,which is adapted to be attracted by the core 6. This armature 14 ispivoted as shown on a thin phosphor bronze strip 12 and an extension ofthis armature has fixed thereto a flexible arm 15 carrying a contact 16.A spring 17 tends to draw the armature 14 away from the magnet 5 and tomaintain contact between contact 16 and a cooperating contact 18.

Another magnet 19 is shown as having a pair of shunt coils 20, 20,connected in selies with each other, the cores 21, 21, being connectedtogether by an iron connecting strip 22. The cores 21, 21 have a commonarmature 23, which is flexibly supported by a phosphor bronze strip 12at one end and carries afiexibly supported contact'18 at its oppositeend. A spring 24 tends to hold this armature 23 away from the cores 21,21' and to hold contact 18 in a direction away from contact 16. a i aThe tension of springs 13, 17 and 24 is preferably adjustable in anysuitable manner, a portion of the lower end of spring 24 being shown insection and broken away to indicate one form of adjustment comprising ascrew plug adapted to turn within theend of the spring. To make thisadjustment the spring is unhooked and the screw plug turned asdesired-after which the spring is again hooked. Any suitable 'form ofadjusting means may e used. I also provide for adjusting the position ofthe stationary contact 11.

As above stated, the contacts 16 and 18 are yieldably supported byflexible supports; the stationary contact 11 is also yieldably supportedby a flexible support so that when the contacts are closed, there is aslight sliding movement of one contact upon the other. This action tendsto burnish and clean the contacts giving good electrical connection andprevents accumulation of oxid or other current resisting material. Iprefer to make the contacts of pure silver on account of its desirablequalities. The mass of the vibratory elements, particularly thevibratory element 14 is made as small as is con- 'sistent with obtaininga satisfactory magnetic pull and contact. The acceleration of the lightmass under the action of the magnet or under the action of the spring iscon-- sequently very rapid and assists in giving a rapid make and arapid break of the concircuited by means of the vibratory element I 14.A series of four connection terminals 31, are shown in Fig. 1 forconnection to the leads from the battery 4, armature 2 and field winding3 as shown in Fig. 1.

Referring more particularly to Fi 2, which shows the connections of thea ove described apparatus, one lead from the armature 2 is showndirectly connected to one terminal of the battery 4. The other terminalof the battery is connected to the series coil 8, from which aconnection extends 11 to the stationary contact 11. When contact 10engages contact l1,'the main circuit is closed through the extending armof the armature 9 to its support and thence to the other terminal of thearmature 2. WVhien the contacts lO and 11 are separated, this chargingcircuit is open and the armature is then disconnected from the battery.

One terminal of the field winding 3 is connected to one terminal of thearmature, the remaining terminal of the field winding 3 being connectedthrough the resistance 30 to the remaining terminal of the armature.When the vibratory contact 16 is in engage ment with the contact 18, thefield resistance 30 is short-circuited, the current passand 16 throughan extension of armature 14 31 for starting the gas engine1,incandescent lampjs 32, ignition means 33, and electric horn 34, orany other suitable translating devices. .I

he armature 9 and its contact serves as an automatic cut out switchwhich automatically comiects'the dynamo armature to the battery when thedynamo voltage is properly high; this is accomplished by the shuntwinding 7 connected across the dynamo terminals and which when thevoltage generated by the dynamo attains a predetermmed amount, causesthe armature 9 to be attracted and so closes the charging circuit. A

' reduction of armaturevoltagebelow 'a certain proper amount will permitthe spring 13 to separate the contacts 10 and 11 an thus disconnect thedynamo from the battery.

When the charging circuit is closed,.the series current coil 8 thenexerts a force tending to attract the armature 14;'which is additive, tothat exerted by the shunt coil 7. Assuming that the armature 23 is heldb the spring 24 away from the cores of the s unt coils, 20, 20", thenwhen the charging current passing through the series coil 8 attains acertain maximum, the armature 14 will be attracted and separate thecontacts 16,18, which resultsv in connectin the high resistance 30 inseries with the eld winding 3 of the dynamo. This resistance isproportioned to then cause a reduction in the volt age and currentdelivered by the dynamo armature to such an amount that the attractiveforce exerted upon the armature 14 is insufficient to hold the armatureagainst the force of the spring 17, which results in the closing of thecontacts 16 and 18. This short-circuits the resistance 30 which causessuch increase in the current through the field winding 3 as to cause thevoltage and current delivered by the dynamo to rapidly use.

It will be noted that the series windin 8 responds to the total currentdelivered by the dynamo to the battery and to any of the translatingdevices which may be in use. This controlling series winding resultsin-so controlling the field of the dynamo as above described, as tocause a fluctuating current to How from the dynamo which fluctuatingcurrent integrates to a substantially steady current.

When the vibratory contact 18 engages contact 18 and short-circuits thehigh resistance as above explained, the voltage of the dynamo rapidlybuilds up, but although this rise of voltage is extremely rapid, it is asmooth, gradual rise of voltage and not such an abrupt or instantaneousone as occurs by cuttmg out a resistance in series with a device acrossa constant voltage circult and in the absence of inductive effect.

This rapid smooth rise in voltage at the dynamo brushes causes a rapidbut smooth increase in the current through the work circuit and throughthe series coil 8-. This current will contlnue to increase 'until themagnetic pull upon the armature or keeper 14 forcibly and quicklyvseparates the contact 16 from the contact 18. The resultin introductionof the resistance in the fiel circuit instantly. prevents the dynamovolta e from increasing any further and it begins to rapidly fall aswell as the current in the work circuit passing through the series coil8, although this rapid fall of current is a gradual, smooth reduction ofcurrent. If

not arrested, a current due to the voltage of the battery would flowbackward in the cincuit from the battery to the dynamo arma ture. Thiswould cause .the series current in coil 8 to oppose th'e-efl'ect of theshunt coil 7 and thereby'cause the instantaneous opening of the maincircuit by the armature 9. But before such a condition is reached,

the current through the series coil 8 in its fall from its maximum valuereaches such a I reduced value that the spring 17 overpowers until themagnetic force again quickly sepav rates the contact 16 from contact 18and again inserts high resistance 30 in the shunt field circuit. thisaction being constantly repeated. When the resistance 30 isshortcircuited or cut out, the current in the series coil 8 willcontinue to rise rapidly and almost indefinitely until the contact 16has separated from contact 18. This is due to the proportion of thefield and resistance-30 and also due to the fact that the ohmicresistance in the circuit including the dynamo armature and the batteryis extremely low and a comparatively small increase in voltage of thedynamo therefore makes a large change in current through the battery andseries coil 8. But even a large change in the current through thebattery does not mathe increase of voltage due to the current passingthrough the low batterv resistance is very low compared with the normalcountervolts' of the battery and thecounter-volts in the batteryaresubstantially independent of the current through the battery. It ispractically impossible for'the contacts 16 and 18 to stick or ffreeze asit is sometimes called. If they should remain closed, the magnetic forcetending to pull the contact 16 open, will rise to many times the normalforce needed to overcome the sprin 17, and the current to the magneticWin ing 8 would continue to rise until the contacts were separated. Theaction in opening the contacts is comparable to the opening of anoverload circuit breaker, and limits the maximum amperes to a certainamount, and therefore prevents abnormal heating and sparking, even ifthe counter-volts of the battery should be abnormally low, or if theresistance of the circuit should be abnormally low due to ashort-circuit. Therefore, in practice fuses or equivalent overloadprotective devices are entirely unnecessary. .The opening is so rapidand positive that the arcing at the contacts is reduced to a minimum andin practice is entirely negligible and does not cause any materialdepreciation of the contacts.

If the work circuit did not comprise the low resistance storage battery,or some equivalent low resistance counter electromotive force device,but merely had devices such as incandescent lamps, field windings,

- or other similar devices which oppose considerable ohmic resistance tothe flow of current, then evidently a large percentage in-' crease ofcurrent in the work circuit would require a large percentage increase ofthe dynamo voltage. This would require a large percentage increase involtage upon the incandescent lamps which is just what should beavoided. Also in systems in which the vibratory switch is responsiveentirely or mainly to the voltage, it is evident that if the contactsshould stick and it became necessary to develop twice the normal forceto .separate them, it would require twice the voltage, because theampere turns would be proportionate to the voltage. This would give avery excessive and objectionable current through the dynamo armature andthe.

battery,as.well as a very excessive and objectionable voltage upon theincandescent lamps. By my invention however, the equivalent increase of100% in the ampere turns of the controlling series coil 8 would beaccomplished by a very slight increase in the voltage of the dynamoandonly a momentary increase in the current through the dynamo.

Considering now the action of the armature 23 as controlled by the shuntcoils 20, 20', the function of this device in its relation to thevibratory element 14 is to make a pronounced change'in the averagecharging rate, or average current delivered by the generator armatureafter a certain condition of the circuit has been obtained. This isaccomplished in this instance by changing the reluctance of the magneticcircuit of the magnet 5 by bringing the armature 14 nearer to the core 6when the armature 14 is in its outermost position. In the action abovedescribed the armature 23 was assumed to be held in its outer positionby the spring 24. When, however, the magnetic attraction caused by theshunt coils 20, 20 attains a certain amount, the force of the spring 24is overcome and the armature 23 is brought to a position nearer thecores 21, 21 against the adjustable stop 27'. This gives a new positionto the contact 18 and thereby holds the contact 16 when in engagementwith the contact 18 in a new position and brings the armature 14 so thatits outer position under these conditions is less than its outerposition before the armature 23 is attracted by the cores 21, 21.Consequently, the armature 14 with the new position of the contact 18,will be attracted by a smaller maximum current 'in the work circuitthrough the coil 8 than before. The result will be that the element 14will now vibrate, making and breaking contact between the contacts 16and 18, but the maximum limit of the current being much less thanbefore, the average current under this condition Willbe much less.

In the present instance, the controlling factor in the change of theaverage charging rate, or in the average current delivered by thegenerator, is the voltage attained by the generator and the battery, orin other Words, the Voltage of the work circuit. The-controlling magnet19 is proportioned and parts adjusted so that when the battery is notfully charged or when a number of consumption devices. are takingconsiderable current, resulting in the electromotive force of thecircuit being less than when the battery is at the maximum limit, thespring 24 will exert a force greater than the attractive force exertedby the voltage coils 20, 20 upon the armature 23. The armature 23 willconsequently be held against the stop 27 during such conditions. When,however,

one-tenth to one-fifth of the 'maximum charging rate. .In this way, Iavoid the unnecessary driving off of the wateriof the electrolyte to anyobjectionable degreef' 'l'n the usual system, it 1s ncessaryto put ad!ten happens that this-addition of water at the proper time isoverlooked. This exposes the battery plates and tends to damage them and.also reduces the battery capacity for starting and lighting hap ensthat nothavmg pure water readily avallable, the operator will put inimpure water with consequent depreciation of the battery.

Another advantage of my invention is that the customary ampere meter Ain the path of the battery current becomes a simple and reliableindicator of the condition of the battery. Suppose the maximum rate is10 amperes, and the minimum rate is 1 ampere. As soon as the battery isinperfectly charged or nearly charged condition, the ampere meterautomatically records one ampere; as long as this reading is observed,

the operator lmows that his battery is in perfect condition. v

As soon as the use of current. from the battery lowers the voltagematerially, due for example to the use of the side lights and tail lightwhen the car is standing still, the current will automatically charge atthe maximum rate of say 10 amperes when the engine is-st'arted, and thiswill continue until the battery is sufliciently charged. .Of course, ifsome lamps or other translating devices are in use, the current theytake will be deducted from the assumed 10 amperes and the balance willcharge the battery.

The dynamo can be made the smallest, cheapest and lightest for the dutyby means of my invention, as its maximum duty is actually known and thismaximum duty is antomatically employed whenever it is needed. In othersystems the maximum amperes are not accurately known or automaticallylim- Y ited and the dynamo must therefore be made larger and heavier inorder to have a safe margin for the largwt currents. Also in othersystems, where a voltage control is an essential one, the currentgenerated may be much less than the maximum desirable amount andmay becut down to say, 5 amperes when in accordance wlth my lnventlon,

the dynamo would be advantageously operated to deliver 10 amperes. Inorder to compensate for this difference, such other systems are obligedto have a higher maximum current capacity in order to compensate for thesmall current which is delivered part of the time.

In order to have the magnetic effect of the voltage winding 20, 20,unaffected by result. purposes. It often changes of temperature betweendifferent seasons of the year and also practically unafi'ected bytheheat due to, the current, I prefer to employ means for having theresistance of this voltage circuit substantially constant andindependent of such temperature chan es. For this u so I referabl usewire in the coils QOPQd Tif zerg temperzi ture co-efi'lcient, or nearlyzero co-efficient, such as German silver, although I may employ otherknown means or obtaining the desired -While I have shown a shunt il 7 onthe same core as the series coil 8, this shunt coil is in many formsofmy invention, merely an. auxiliary one and not an essential one. preferto combine the self-closing switch responsive to the voltage whichcloses the main circuit, with the vibratory controlling switch-andwinding 8. This is done mainly to save space and cost. These twowindings, however, may if desired be separate and act separately uponthe armatures which they respectively control.

By placing these two windings 7 and 8 on a common core however, I get 'aslightly tapered charging current when the high rate is in use. Forexample, the charging current may be 11 amperes when the battery voltageis low, and the efiect of the voltage coil 7 is therefore lower thanusual. As the charging proceeds, this current will slowly and graduallyfall as the voltage slowly rises, and may come down gradually to say 9amperes. Then, suddenly, when the batteryreaches the proper state ofcharge, the voltage winding 20, 20' will attract the armature 23 andthus cause the reluctance of the magnetic circuit of the controllingmagnet to be changed causing the current to drop to the low rate of thebi-rate system which may be say, 1 or 2 amperes.

It will be understood that by means of the adjustable stops, the airgaps may be adjusted so as to predetermine the maximum average amperes,the-minimum average amperes and the voltage at which the rate changesfrom the maximum to the minimum average rate.

-In some cases it is desirable to havethe voltage winding 7 produce theprincipal part of the magnetizing effect and. have the se .ries winding8 produce less amount. In

Fig. 2, except that the current from the ar-.

mature of the dynamo passes through the series coil 8 before reachingthe contacts 10 and 11, which control the main circuit; also the fieldcircuit connection instead of being directly across the armature, isconnected at 35 in the main circuit, giving a field connection acrossboth the armature 2 and the series coil 8. Consequently the series coil8 carries not only the armature current, but also the shunt fieldcurrent, and consequently the wide fluctuations in the field currenttend to furnish desirable pronounced fluctuations of magnetism in thecore 6, even if the principal magnetic effect is due to the large coil7. This arrangement of circuits proves very useful in many cases.

In some cases I use three windings on the core 6, two of the windingsbeing the shunt winding 7 and the series windmg 8, and v the thirdwinding being connected in series in the shunt field circuit asillustrated n Fig. 4. The circuits and connections of this figure arethe same as those of Fig. 2, except the coil 36 is added to the core 6,whlch coil is in series with the fieldcoil 3 of the generator, whetherthe resistance 30 is in or out of the field circuit. When the connectionof this winding 36 is such that the current passing through it isdifl'erentlal or opposing the effect of the charging current in thewinding 8 and the current in the voltage winding 7 the advantage isobtained of causing the value of'the charging current to decreasesomewhat as the speed of the dynamo increases. This is because theaverage field current decreases as the dynamo speed increases, givingless oppos1t1on-to the magnetic effect of the windings 7 and 8 so thatthe vibrating contact will cause the insertion of the field resistanceat a lesser maximum value of the current through the series winding 8and thereby cause a decreased value of charging current when the speedincreases.

Instead of securing the bi-rate control by changing the reluctance asabove described, the same effect maybe obtained by changing any of thefactors controlling the opening and closing of the circuit atnthecontacts 16 and.18. Thus, instead of changing the position of thecontact 18 to cause the change of reluctance above described, themagnetic effect of the voltage windings 20, 20 may be used to change thetension of the spring 17 by means of the two different po-' sitions ofthe armature 23. Thus, in Fig. 5, the armature of the windings 20, 20'is designated as 23 and at its outer end is connected the spring 17corresponding to the spring 17, the other end of the spring beingconnected to one of the ends of the vibratory element 14. Instead ofhaving the contact 18 carried by and actuated by the armature 23, thecontact in this case is stationary and represented in Fig. 5 by thestationary contact 18', the electrical connection from one terminal ofthe field winding 3 passing directly to the stationary contact 18'instead of through the armature 23. Except for these changes, thearrangement of Fig. is the same as that of Fig. 2. In considering theoperation of the construction indicated in Fig. 5, the armature 23' willbe held away from the volta e windings 20, 20 when the voltage of t ebattery circuit is below a predetermined amount giving the highesttension on the spring -17 so as to cause charging of the battery at thehigher rate. When-the voltage is suflicient to cause the voltagewindings 20,20 to attract the armature 23' against the tension of thespring 24 and to move the armature 23' to a position nearer the. voltagewindings, the tension of thespring 17' in the new position is lessenedso that a reduced magnetic force will attract the vibratory element 14and consequently cause the charging current to be reduced to the'lowervalue. It will also be understood that the armature 23 of Figs. 1 to 4,instead of being utilized to change the position of contact 18 and sochanging the reluctance, and instead of being utilized to change thetension of thespring 17 as in Fig. 5, might be utilized in its twopositions to change the number of effective turns in the series winding8, as indicated in Fig. 6, increasin the number of turns in circuit ofthe windlng 8 for the low charging rate, and decreasing them for thehigher charging rate. Various other modifications may be made and theautomatic control of the change in the charging rate may be secured asabove stated by other than the electromagnetic means herein shown.

lVhile I have described the application of my invention to a chargingbattery system, it may have other applications as to certain of itsfeatures. Thus, it may be useful in electrodeposition, electric furnaceoperations, electric heating, and many other fields where it isdesirable to have an electric current employed at a'higher rate until acertain condition results and then in response to such condition to havethe current automatically reduced to a lower rate.

Having thus described my invention, what I declare as new and desire tosecure by Letters Patent of the United States is 1. The combination of adynamo, a magnetic winding having a movable element automaticallymovable to change the field strength of the dynamo when the currentthrough said winding reaches a certain value, and a second magneticwinding automatically responsive to a condition of a circuit supplied bysaid dynamo for changing the reluctance of said first magnetic windingand thereby automatically changing the output of the dynamo.

2. The combination with a source of electric current, of anelectricswitch, a spring tending to hold said switch in closed position,a magnet for moving said switch to its open position when sufiicientlyenergized, a

the reluctance of said first magnetic device when the voltage acrosssaid circuit reaches a certain value.

4. The combination with an electric circuit, of a magnetic winding, amovable magnetic element controlled thereby, a spring tending to movesaid element in a direction opposite to that in which the magnetism ofsaid magnetic winding tends to move it, a stop for limiting the movementof said element when moved by said spring, a second magnetic winding, acore therefor, an armature narrowly spaced from the poles of said coreand carrying said stop, and front and back stops for said armaturewhereby said first mentioned stop is controlled to stand at one of twodefinite alternative positions.

5. The combination of an electric circuit, and two electromagneticwindings functionally related to said circuit and to each other, one ofsaid windings responding to an electric condition of said circuit tochange the reluctance of the magnetic circuit of the other of said twowindings and thereby control the energy in said circuit.

6. The combination of an electric circuit, and means for controlling thecurrent in said circuit, comprising two functionally related windings,one of said windings being adapted to change the reluctance of themagnetic circuit of the other of said windin s and thereby controlcurrent through said latter windin 7. The combination of a source ofelectric energy, a circuit supplied thereby; an electro-magnet having amovable armature for controlling the energy in said circuit, and asecond electro-magnet having a movable armature, the movement of whichcauses a change in the reluctance of the magnetic circuit of said firstmagnet. for effecting the control of the movable armature by said firstelectro-magnct.

8. A dynamo having a shunt field winding, a storage battery, lampsconnected in parallel with said battery, said battery and lamps beingsupplied with current from said dynamo, a movable magnetic element carrying switch contact, a magnetic winding energized by current from saiddynamo for controlling the movement of said element, a cooperatingswitch contact, a spring tending to hold said contacts closed, theclosing and opening of said contacts controlling the field strength ofsaid dynamo by the rapid vibration of said element in response to energysupplied by said dynamo, and a second magnetic winding supplied byenergy derived from said dynamo for changing the control effected bysaid first magnetic winding.

9. A storage battery, a dynamo for charging said battery, and automaticmeans for controlling the output of the dynamo-comprising a vibratoryregulator, a back stop therefor adjustable to either of two positionsonly, and a voltage winding to control said back stop, the current inwhich is substantially independent of temperature changes.

10. The combination of a dynamo and automatic means for controlling theoutput of said dynamo comprising a vibratory regulator, a back stoptherefor adjustable to either of two positions only, a series coil togovern said vibratory regulator and a shunt coil to control said backstop, the current in winding being substantially unaffected by changesin temperature.

12. The combination with an electric circuit, a magnetic device forcontrolling the current in said circuit and having a copper winding,asecond magnetic device having a winding of low temperatureco-ellicicnt, and means for causing the second winding to effect theperformance of said first winding when the voltage upon said circuitreaches a certain value.

In testimony whereof I ailix my signature.

in presence of two witnesses.

. I'l. \VARI) LEONARD.

Witnesses:

L. K. Sacra, B. E. SMYTII.

